From Concrete to Abstract: Teaching for Transfer of Learning when Using Manipulatives

One of the most important uses of manipulatives in a classroom is to aid a learner to make connection from tangible concrete object to its abstraction. In this paper we discuss how teacher educators can foster deeper understanding of how manipulatives facilitate student learning of math concepts by emphasizing the connection between concrete objects and math symbolization with, preservice elementary teachers, the future implementers of knowledge. We provide an example and a model, with specific steps of how teacher educators can effectively demonstrate connections between concrete objects and abstract math concepts.

Transfer Pricing in the Decentralized Multinational Corporation

This paper considers how the multinational corporation's transfer price responds to changes in international corporate effective tax rates. It extends the decentralized decision-making analysis of transfer pricing in the context of different tax rates. It adopts and extends Bond's (1980) model of the decentralized multinational corporation that assumes centralized transfer pricing. The direction of transfer price change is as expected, while the magnitude of change is likely to be less than predicted by the Horst (1971), centralized decision-making model. The paper extends the model further by assuming negotiated transfer pricing, where the analysis is partitioned into perfect and imperfect information cases. The negotiated transfer pricing result reverts to the Horst (1971), or centralized decision-making, result, under perfect information. Under imperfect information, the centralized decision-making result obtains when top management successfully informs division general managers or it successfully implements a non-monetary reward scheme to encourage division general managers to cooperate. Under simplifying assumptions, centralized decision-making dominates decentralized decision-making, while negotiated transfer pricing weakly dominates centralized transfer pricing.

A Bargaining Model of Holdouts and Takings

The holdout problem is commonly cited as the justification for eminent domain, but the nature of the problem is not well understood. This paper models the holdout problem in a bargaining framework, where a developer seeks to acquire several parcels of land for a large-scale development. We show that in the absence of eminent domain, holdouts are inevitable, threatening costly delay. However, if the developer has the power to use eminent domain to acquire the land from holdouts, all sellers will bargain, thus avoiding delay. An offsetting cost is that owners may negotiate prices below their true value, possibly resulting in excessive transfer of land to the developer.

Guinea Pigs: A Suitable Animal Model to Study Lipoprotein Metabolism, Atherosclerosis and Inflammation

Numerous animal models have been used to study diet effects on cholesterol and lipoprotein metabolism. However, most of those models differ from humans in the plasma distribution of cholesterol and in the processing of lipoproteins in the plasma compartment. Although transgenic or knock-out mice have been used to study a specific pathway involved in cholesterol metabolism, these data are of limited use because other metabolic pathways and responses to interventions may differ from the human condition.Carbohydrate restricted diets have been shown to reduce plasma triglycerides, increase HDL cholesterol and promote the formation of larger, less atherogenic LDL. However, the mechanisms behind these responses and the relation to atherosclerotic events in the aorta have not been explored in detail due to the lack of an appropriate animal model. Guinea pigs carry the majority of the cholesterol in LDL and possess cholesterol ester transfer protein and lipoprotein lipase activities, which results in reverse cholesterol transport and delipidation cascades equivalent to the human situation. Further, carbohydrate restriction has been shown to alter the distribution of LDL subfractions, to decrease cholesterol accumulation in aortas and to decrease aortic cytokine expression. It is the purpose of this review to discuss the use of guinea pigs as useful models to evaluate diet effects on lipoprotein metabolism, atherosclerosis and inflammation with an emphasis on carbohydrate restricted diets.